Summaries of articles in this issue

Abstract

CT scanning F A Mettler Jr et al (353-9) This paper describes the uses of CT scanning and theresulting radiation doses in a mid-sized level III trauma centerteaching hospital. The percentage of CT examinations rose from6.1% ofall radiology procedures in 1990 to 11.1% in 1999. CT scanning accountedfor 67% of the effective dose from diagnostic radiology. The highestpercentage of scans was done on the 36 to 50 year old age group.Children age 0 to 15 years comprised 11.2% of the examined population.The results and conclusions are similar to those that would be obtainedin other US hospitals with greater than 100 beds.The Nord-Cotentin radioecological study C Rommens et al (361-80) A radioecological study wasperformed by a group of experts with various backgrounds - theNord-Cotentin Radioecology Group - to respond to public concern about anexcess number of leukaemia cases in the Nord-Cotentin region of France. Itsprincipal objective was to assess realistically the exposure to ionisingradiation of young people who had lived near the La Hague nuclearreprocessing plant and to estimate their risk of radiation-inducedleukaemia from 1978 through 1996. The number of cases ofradiation-induced leukaemia attributable to discharges from the localnuclear facilities was around 0.002 over this period.Cancer experience of Capenhurst nuclear workers D McGeoghegan and K Binks (381-401) The health experience, as measured bycause of death 1946-1995 and cancer registrations 1971-1991, of allworkers ever employed at the Capenhurst uranium enrichment facility ispresented. The standardised mortality ratios were found to besignificantly low, indicating the usual healthy worker effect. Thestandardised registration rates were also low, though not significantlyso. The death rate for radiation workers was significantly lower thanthat of non-radiation workers. Only bladder cancer, with 14registrations, was found to have a statistically significant(p = 0.035)trend with cumulative external radiation.Validation of an environmental model used for radiological safetyassessments M C Thorne et al (403-21) Radionuclides released from a repository for solidradioactive wastes can be transported in groundwaters and dischargedinto the surface environment. In the UK, the SHETRAN model has been usedto represent the dispersion of such radionuclide discharges in thenear-surface hydrological system, as an input to post-closureradiological safety assessments. Herein, a blind field validation ofSHETRAN for subsurface tracer transport on a spatial scale of a fewmetres is reported. Overall, the SHETRAN system performed well,confirming that it comprises a powerful tool for application inpost-closure radiological safety assessments.Radioactivity in gas lantern mantles E Furuta et al (423-31) Gas lanterns create a warm ambiancewith their incandescent lights which are efficiently producedwhen the lantern fuel burns. Thorium oxide has been believedto be an indispensable component of the mantles to obtain incandescence. Wemeasured gamma-rays emitted from the daughter nuclides of thorium in themantles. The results revealed there are both radioactive andnon-radioactive mantles on the market. The non-radioactive mantles are asbright as the radioactive ones. However, the mantels are soldwithout information concerning radioactivity, which is essentialif customers are to decide to purchase non-radioactive consumerproducts.`Hot particles' in the vicinity of Sellafield A J Whittall et al (433-42) In a survey ofenvironmental samples in the vicinity of BNFL Sellafield, twoalpha-emitting radioactive particles were found in samples of grass. Oneparticle appears to be of mineral origin, the other was not definitivelyidentified, but may be a fragment of fuel cladding. Conservativeestimates of the activities of these particles are very low. Theabundance of radioactive particles in the terrestrial food chain appearsto be low, with no evidence for any alpha-emitting hot particles infoodstuffs for consumption by humans. Results suggest that there is nosignificant dose to man through inhalation or ingestionpathways.HSE performance tests R Birch et al (443-51) Results of performance tests for routine wholebody, routine extremity/skin, and special accident dosimetry, carriedout over the past six years by the AEA Technology Calibration Service atWinfrith, and DRaStaC, the AWE Calibration Service at Aldermaston, arepresented. The results are compared with the pass criteria specified bythe UK Health and Safety Executive for the approval of dosimetry services.